Rail bond



Apl 8 1941 N. G. cARLso 2,237,698

RAIL BOND Filed Sept. 28, 1938 INVENTOR.

BY 7766/66'. Cap/60)@ @Cl/l, y gj) ATTORNE 6.

Patented Apr. 81, 1.941Y

tJNlTED STATES PATE RAIL BUND Noble G. Carlson, Cleveland Heights, Ohio, assignor to The Electric Railway Improvement Company, Cleveland, Ohio, a corporation of Ohio IApplication September 28, 1938, Serial No. 232,154

2 Claims.

of adjoining rail sections at points spaced from the ends of the base of the usual splice bar which connects said rail sections.

lin order to avoid undue or sharp bending of the strands of the relatively soft copper conductor, a-t points adjacent the ends of the splice bar, when securing the terminals to the rail bases, Which might result in breakage or excessive strain on the conductor at these points, it has been customary to make the conductor sufficiently long so that it extends considerably beyond the ends of the splice bar, as shown, for example, in my Patent No. 2,109,791. In actual practice, the overall length of the rail bond is about 8 in excess of that of the splice bar.

This has several disadvantages, among which l may be enumerated the following:

l. The electrical resistivity of the rail bond, being proportional to the length thereof, is higher than that of a shorter rail bond.

2. rlhe stranded conductor is exposed at point f adjacent the ends of the splice bar, and in case of derailrnent, which frequently occurs in mine car operation, the strands may be abraded or severed by the wheels of the derailed car, such wheels coacting with the sharp upper edges of the ends of the splice bar to produce a shearing action.

3. The cost of the stranded conductor, being proportional to the length thereof, is greater than that of a shorter conductor.

The present invention accordingly has as its primary object the provision of a rail bond of low electrical resistivity and which is well adapted while in situ to withstand injury resulting from derailed cars, etc.

Another object of the invention is to provide a rail bond having terminals of novel and improved construction.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain structure embodying the invention, such disclosed means constituting, however, but a few of various structural forms in which the principle ofthe invention may be used.

In said annexed drawing:

Fig. l is a fragmentary perspective viewshowing a preferred form of rail bond installed in accordance with the invention;

Fig. 2 is an enlarged perspective view of one end of the rail bond;

Fig. 3 is a longitudinal cross-sectional view taken on the 'line 3-3 of Fig. 1;

Fig. 4 is a transverse cross-sectional view taken on the line 4 4 of Fig, 3;

Fig. 5 is a view similar to Fig. 3, but showing f a somewhat modified form of rail bond;

Fig. 6 is an end elevation of the rail bond of Fig. 5;

Fig. 'l is la view similar to Fig. 3, but showing a still further modified form of rail bond.

Referring more particularly to that form of the invention shown in Figs. 1 to` 4 inclusive, there is disclosed in Fig. 1 a rail R, having a base B, such rail being connected to an adjoining rail section (not shown), by means of a splice bar F having the usual base portion FB which overlies the bases B of the adjoining rail sections. As noted in Figs. 3 and 4, the base portion FB is of considerable thickness, in this case about 1/2".

The rail bond proper consists of a conductor body I, formed from a stranded copper cable, sleeves 2, formed of copper or copper alloy tubing or strip, which are secured to the ends of the conductor body l, and terminals 3, which are secured to the sleeves 2.

The sleeves and portions of the conductor body that enter therein are attened by means of a suitable die under a hammer or press, so that the strands of the conductor are left in tightly compressed condition, as shown in Figs. 3 and 4. The flattening of the sleeves is graduated at their inner ends, the sleeves being left in their original approximately circular form at such ends so that the entering strands may have a slight amount of relative movement at the points in question. |Ihe flattened portions of the cable I and sleeves 2 are bent to provide downwardly extending portions which lie in planes substantially normal to the axis of the unaltered portion of the body l, and to these downturned portions of the cable and sleeves are secured the terminals 3.

The terminals 3 are preferably in the form of steel forgings or the like, and are frustropyramidal in form, the downturned por-tions of the cable and sleeves extending into such terminals, and the terminals being permanently secured to the former, as by filling the space between the inner walls of the terminals and the cable and sleeves with molten copper or copper alloy 4 and allowing the parts to solidify. The terminals are also provided with hook-like clamps 5 which are adapted to embrace the rail bases, as shown in Fig. 1, for the purpose of maintaining the terminals in proper welding position on such bases.

In installing the rail bond, the cable I is disposed above the base FB of the splice bar F, and the terminals 3 are positioned closely adjacent the ends of such base, as best shown in Fig. 3, and Welded to the rail bases B as by means of weld metal 6.

Due to the provision of the downturned portions of the cable and sleeves, and the attachment of the terminals to such downturned portions, the terminals 3 may be positioned very close to the ends of the base FB of the splice bar F, thereby reducing to a minimum the length of cable required for the rail bond. In actual practice, the overall length of the cable need not exceed the length of the splice bar by more than 2, as compared with the usual 8" required for other rail bonds. There is thus a clear saving of 6 of copper cable for each rail bond, which, in view of the fairly high price of such cable, is an item of considerable importance. By thus reducing the length of copper cable required, the electrical resistivity of the bond between adjoining rail sections is correspondingly reduced.

Moreover, due to the fact that the ends of the rail bond have downturned portions which are preformed, it is not necessary, as in the usual case, to bend downwardly the portions of the cable which extend beyond the ends of the splice bar to enable the terminals of the rail bond to be secured to the rail bases. By thus avoiding undue or sharp bending of the strands of the relatively soft copper conductor at points adjacent the ends E of the splice bar, when securing the terminals to the rail bases, breakage and excessive strain on the conductor are precluded.

It may be further noted that the stranded conductor is covered by the sleeve 2 at points adjacent the sharp upper edges S of the ends E of the splice bar, so that in the event of derailment of a car from the rails R, the strands of the conductor will not be severed as a result of the wheels of the derailed car pressing the conductor against such sharp edges Referring now to that form of the invention shown in Figs, 5 and 6, the rail bond in this 0 case comprises a stranded copper cable I0 having tubular copper or copper alloy sleeves I I secured to the terminal portions thereof. The sleeves are slightly compressed onto the cable, but are not flattened, nor are portions of the sleeves and cable bent to provide downturned portions as in the previously described form of the invention. The cable and sleeves extend into circular openings in the terminals I2, the terminals being permanently secured to the sleeves and cable by means of molten copper or copper alloy I3 which lls the space between the inner Walls of the terminals and the cable and sleeves. 'Ihe terminals I2 in this case are of considerable height, so that it is unnecessary in securing the cable and sleeves to such terminals to bend the cable and sleeves to an extent greater than indicated in Fig. 5. Such a rail bond may be advantageously employed where the base portion of the splice bar is not more than about in thickness. The terminals I2 of this rail bond, as shown in Fig. 6, are also provided with clamps III for embracing the rail bases. Here again, it will be noted that the rail bond is considerably shorter than rail bonds of the ordinary type, the overall length of the rail bond. not exceeding the length of the splice bar by more than about 4". The sleeves II in this case also extend over the edges S of the splice bar, and thus serve to protect the strands of the conductor I0 against abrading or cutting by such edges.

In that form of the invention shown in Fig. 7, the separate terminals are dispensed with, and instead sleeves 2I in the form of steel tubing or the like are employed, which are welded at the end to the stranded conductor 20, flattened and bent. These sleeves are generally similar in form to the sleeves 2 of that form of the invention shown in Fig 2, but extend to the rail bases. By thus dispensing with the separate terminals, the overall length of the rail bond may be reduced to not more than about ll longer than the splice bar. The sleeves 2| in this case eiectively protect the strands of the cable against abrading or cutting by the edges S of the splice bar.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the structure herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In combination with adjoining rail sections and a splice bar connecting said sections, said splice bar having a portion overlying the bases of said rail sections; a rail bond comprising a stranded conductor extending over said portion of said splice bar, sleeves secured to the ends of said conductor and overlying the upper edges of the ends of said portion of said splice bar, portions of said conductor and sleeves being bent to lie in planes substantially normal to the axis of said conductor closely adjacent the ends of said portion of said splice bar, and terminals secured to said sleeves, said terminals being attached to said bases of said rail sections.

2. In combination with adjoining rail sections and a splice bar connecting said rail sections, said splice bar having a portion overlying the bases of said rail sections, a rail bond comprising a stranded conductor extending over said portion of the splice bar and sleeves secured to the terminal portions of said conductor, said sleeves having portions overlying the upper edges of the ends of said portion of the splice bar and said sleeves and terminal portions of said conductor being bent substantially normal to the plane of the body of said conductor, the ends of said conductor being secured to said bases of said rail sections.

NOBLE G. CARLSON. 

